• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.167-179
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• 2024

This study explores the feasibility of employing (U, Th)-based accident tolerant fuels (ATFs), specifically (_0.8UO₂, _0.2ThO₂), (_0.8UN, _0.2ThN), and (_0.8UC, _0.2ThC). The investigation assesses the overall performance of these proposed fuel materials in comparison to the conventional UO₂, focusing on deep neutronic and thermal-hydraulic (Th) analyses. Neutronic analysis utilized the MCNPX code, while COMSOL Multiphysics was employed for thermal-hydraulic analysis. The primary objective of this research is to overcome the limitations associated with traditional UO₂ fuel by exploring alternative fuel materials that offer advantages in terms of abundance and potential improvements in performance and safety. Given the limited abundance of UO₂, long-term sustainable nuclear energy production faces challenges. From a neutronic standpoint, the U-Th based fuels demonstrated remarkable fuel cycle lengths, except (_0.8UN, _0.2ThN), which exhibited the minimum fuel cycle length and, consequently, the lowest fuel burn-up. Regarding thermal-hydraulic performance, (_0.8UN, _0.2ThN) exhibited outstanding performance with significant margins against fuel melting compared to the other materials. Overall, when considering the integrated performance, the most favourable results were obtained with the use of the (_0.8UC, _0.2ThC) fuel configurations. This study contributes valuable insights into the potential benefits of (U, Th)-based ATFs as a promising avenue for enhanced nuclear fuel performance.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.282-291
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• 2010

In line with current speed-up of railroad, a slab track has been increasingly adopted in a bid to secure the safety of track structure as well as to reduce the maintenance cost, and furthermore, the need for commercialization of domestically-developed swing-nose crossing turnout on slab track has been on the rise. For commercialization of swing-nose crossing turnout on slab which was developed in Korea, a technical and systematic performance evaluation system, considering local environment, shall be established and then the performance evaluation shall be accordingly implemented. This paper was intended to summarize the performance evaluation system, referring to the data available at home and abroad and the results of performance evaluation for domestically-developed swing-nose crossing turnout on slab track carried out to date based on that system. A performance evaluation system comprises the technical requirement appropriateness evaluation(component performance evaluation and design verification), laboratory test and on-site test. For domestically-developed swing-nose crossing turnout on slab track, appropriateness evaluation and laboratory test have been completed and the on-site test of those installed on the 2nd phase of Kyung-Bu HSR is underway now.

• Korean Journal of Organic Agriculture
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• v.26 no.1
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• pp.1-17
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• 2018

This study analyzes the management performance of environmentally-friendly rice farms using GCM method based on the multifaceted approach. This approach compares the management performance of GCM farms before and after the introduction of GCM, as well as the performance of GCM farms with the performance of conventional farms. It also compares the technical and managerial competence level of surveyed GCM farms with that of conventional farms based on the standard diagnosis table developed by Rural Development Adminstration. Results showed that average income has increased after the introduction of the GCM method and the average income of GCM farms was higher than that of conventional farms, while the level of rice production in farms using GCM method was lower than that of conventional farms. In addition, the technical and managerial competence score of surveyed farms using GCM method was higher than that of conventional farms. These results implies that the higher management performance of GCM farms compared to the conventional farms is attributed to not only the GCM method but also the competence level of farms using GCM method.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.426-431
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• 2011

The quality of performance evaluation on engineering consultants that provide design-related technical services is difficult to be measured, and only a handful of papers discussed the quality during the design stage. Although design cost is relatively far less than construction cost for a project, the decisions made in the design phase have a significant impact on the final products of the project, especially for large public construction projects. Therefore, this research focuses on reviewing and then establishing a performance evaluation framework for the consulting firms that execute detailed design and provide technical services for the Taipei Rapid Transit Systems (TRTS). By interviewing experts, this study first established a set of indicators to evaluate these firms' performance. Then, those indicators were incorporated into the four aspects of balanced scorecard (BSC) to establish the architecture of the evaluation mechanism. The weight of each indicator was calculated by analytic hierarchy process (AHP) from a survey conducted among experts. The results showed that the top-three indicators were quantity take-off, functions conformity, and budgeting. The framework of performance evaluation established by this study can be applied to measure service performance during the design stage. It not only facilitates the monitoring of consulting firms, but also helps to reduce unnecessary change orders and disputes during the construction stage.

• Journal of Radiation Protection and Research
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• v.33 no.1
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• pp.1-12
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• 2008

International Standardization in all technical area is gaining its momentum as its impact and implication over global trade is directly linked. The worldwide competition to secure a dominant position in the standardization process is ever growing over the years. In 2005, the International Technical Committee on Nuclear Instrumentation, which is a subunit of International Electro-technical Commission (IEC), was held in Korea under the auspices of MOST (Ministry of Science and Technology). Korea has adopted its Rule and Regulation as the National Standard. As a part of a link to National Mid-and Long-term Atomic Energy R&D Program of MOST, the technical development of a performance test for the radiation monitors was carried out under mechanical environment and electromagnetic immunity conditions. The characteristics of the radiation fields were also evaluated under the conditions and introduced to a techniques of performance test for the radiation protection instrumentation adopted IEC61526 standards and it's results was analyzed. We would like to share the experience gained in these efforts, failure as well as success, and to discuss the problems encountered and serious consideration to be taken into account in the future endeavor.

• Fire Science and Engineering
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• v.34 no.2
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• pp.110-119
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• 2020

The National Fire Safety Code (NFSC) sets forth the installation methods and technical standards of firefighting facilities. This information is stipulated in the attached Table 1 of the Enforcement Decree of the Act on Fire Prevention and Installation, Maintenance and Safety Control of Fire-Fighting Systems. The NFSC serves as a foundation for fire prevention and public safety. However, the current version of the NFSC has been under scrutiny due to its delayed enactment and revision process. This is because of its structural inflexibility, time-consuming procedures, and mixed usage of both performance and technical standards. Furthermore, there are difficulties with keeping its unique specialties due to the absence of a specialized, permanent independent entity that enacts, revises, and maintains its standards. Moreover, the NFSC lacks collectivity, openness, and consistency. Therefore, to overcome the aforementioned obstacles, this study investigates the operational and legal status of the NFSC and the problems regarding its enactment and revision process. Further, it presents suggestions for system improvement by analyzing and comparing the information with domestic and foreign counterparts dedicated to managing their similar technical NFSC standards. First, the study recommends that the legal performance and technical standards mixed within the current NFSC should be separated. Second, the enactment and revision of technical standards should be implemented by the private sector and not by the government. Third, technical standards should adopt a user-oriented approach for the code system.

• 대한공업교육학회지
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• v.42 no.2
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• pp.1-19
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• 2017

The purpose of this study is to analyze the job performance hours and reasonable job performance hours of teachers working at secondary level technical vocational education institutes. This study analyzed the differences in the job performance hours and reasonable hours that have been investigated according to special subject teachers and general subject teachers. Based on Job Specifications of Teachers Working at Secondary Level Technical Vocational Education Institutes, the development of research tool was finalized, and questionnaires were used as the research tool. The results of this study are as follows. First, the total job performance hours and total reasonable job performance hours perceived by teachers working at secondary level technical vocational education institutes were found to be 2,787.8 minutes and 2,934.7 minutes respectively with a difference of 146.9 minutes. In regards to the job category-specific job performance hours, they were found to be high in the order of lesson administration, extracurricular student guidance, school affairs and administrative duties, and lesson preparation and planning, while the reasonable job performance hours were found to be high in the order of lesson administration, lesson preparation and planning, extracurricular student guidance, and school affairs and administrative duties. As for the job categories with shorter reasonable job performance hours compared to job performance hours, they were found to be lesson administration, extracurricular student guidance, and school affairs and administrative duties. In other job categories, it was found that longer job performance hours are needed. Second, the job performance hours perceived by each subject teacher from other schools, they were found to be 2,888.3 minutes for special subject teachers and 2,536.1 minutes for general subject teachers, while showing 3,021.8 minutes for special subject teachers and 2,716.8 minutes for general subject teachers regarding reasonable job performance hours. The differences between the job performance hours and reasonable job performance hours perceived by teachers from other schools were found to be 133.5 minutes for special subject teachers and 180.7 minutes for general subject teachers.

• Journal of Engineering Education Research
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• v.17 no.1
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• pp.3-11
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• 2014

The purpose of this study was to verity the effect of project method on the task performance ability in development of a solar-tracking-control-system of specialized high school. In order to carry out this study, 2 classes of technical high school in Jeonbuk are chosen as experimental and control groups. The experimental group was taught by project method and the control group was taught by traditional instruction. Project method was designed by 4 stages-selection of goal, planning, implementation and evaluation. According to these stages, experimental group's students carried out the project that developing solar tracking control system in solar generation. The results of this study are as follows; the project method was more effective than the traditional instruction in planning ability for task performance and implementation ability, subordinates of task performance ability. However, information gathering ability and evaluation ability on task performance, others in subordinates, it is not clear that the project method is more effective.

• ETRI Journal
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• v.33 no.5
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• pp.670-678
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• 2011

This paper investigates the design and performance of a digital on-channel repeater (DOCR) for use in Advanced Television Systems Committee (ATSC) digital television (DTV) broadcasting. The main drawback of a DOCR is the echo interference caused by coupling between transmitter and receiver antennas, which induces system instability and performance degradation. In order to overcome this problem, an echo canceller based on the adaptive echo channel estimation (ECE) technique has been researched and applied for a DOCR. However, in the case of ATSC, the pilot signal, which is used for carrier synchronization, may cause a DC offset error and reduce the isolation performance of the echo canceller for a DOCR in an ATSC network. Moreover, since the multipath fading effect of a radio channel usually occurs in a real environment, it should be minimized to improve the overall performance of a DOCR. Therefore, due to the limited isolation performance of echo canceller and the multipath fading effect, an interference cancellation system (ICS) is proposed for a DOCR in an ATSC network. The performance of the proposed DOCR with an ICS is evaluated by software simulation and hardware test results.

• Journal of electromagnetic engineering and science
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• v.3 no.2
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• pp.99-103
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• 2003

For mobile multimedia systems that equip transmit diversity for a forward channel, it is well known that the Tx diversity technique is appropriate for high rate mobile multimedia communications. In this paper, we propose a STTD (Space Time Transmit Diversity) receiver, which incorporates the design of the Tx diversity receiver without the mutual interference of antenna by using a CCI cancellation technique. The new STTD receiver is simulated and its performance is analyzed in a DS-CDMA/QPSK. Adopting the proposed STTD receiver at $10^{-2}$TEX>∼$10^{-4}$TEX> in bit error rate, SNR of 0.5 ㏈∼2 ㏈ performance improvement in AWGN and Rayleigh fading environments has been achieved.